Operating electronic devices at a reduced power level may yield benefits such as reduced current leakage, reduced dynamic energy, extended battery life, and reduced heat generation.
System-on-chip devices may reap the benefits of selective power management by associating devices with different power domains called “voltage islands” or “power islands” that receive different voltage levels even within a same physical device. However, a potential problem may exist when a first voltage island operating at a first voltage level provides a signal to a second voltage island operating at a higher voltage level. A first voltage threshold used to differentiate between a high output signal (e.g., logic “1”) and a low output signal (e.g., logic “0”) for circuits within the first voltage island may be below a second voltage threshold for circuits within the second voltage island. As a result, a high output signal (e.g., logic “1”) of the circuits within the first voltage island may be below the second voltage threshold, and the signal may be misinterpreted as a low output signal (e.g., logic “0”) by the circuits within the second voltage island.
To facilitate communication between differently powered voltage islands, voltage level translators may be used to amplify output signals of circuits of voltage islands operating at a reduced power to expected input levels of circuits operating at a higher power. Voltage level translators, however, may consume appreciable power in amplifying signals, and voltage translation of signals may result in signal latency. Further, having to rely on voltage level translators between voltage islands may limit the granularity to which the voltage islands are partitioned because of the additional power overhead associated with level translators. There is therefore a need to enable voltage islands that operate at different voltage levels to efficiently and accurately communicate with one another.